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Definition: This calculator determines the initial number of moles of a substance before dissociation occurs, based on the equilibrium moles, degree of dissociation, and stoichiometry.
Purpose: It's essential for chemical equilibrium calculations, particularly for dissociation reactions in physical chemistry.
The calculator uses the formula:
Where:
Explanation: The formula accounts for how the initial moles relate to equilibrium moles considering the extent of dissociation and stoichiometry.
Details: Accurate calculation of initial moles is crucial for reaction stoichiometry, equilibrium constant determination, and reaction yield predictions.
Tips: Enter the total moles at equilibrium, degree of dissociation (default 0.35), and number of moles from the balanced equation (default 2). The degree must be between 0 and 1.
Q1: What does degree of dissociation mean?
A: It's the fraction of molecules that dissociate into smaller components (0 = no dissociation, 1 = complete dissociation).
Q2: How do I determine the number of moles (Nmoles)?
A: This comes from the balanced chemical equation (e.g., for 2AB → 2A + B2, Nmoles = 2).
Q3: What's a typical degree of dissociation value?
A: It varies by compound and conditions. Weak acids might have α ≈ 0.01-0.1, while strong acids approach 1.
Q4: Can this be used for association reactions?
A: Yes, but the interpretation changes - the formula would represent moles before association occurs.
Q5: What units are used?
A: All values are in moles (amount of substance), except α which is unitless.